An automobile has many electric wires for electrically connecting its engine room and passenger room across a partitioning panel separating the two rooms. A typical grommet, fitted in a hole of the panel for receiving the wiring harnesses passing there through, is made of a resilient material such as rubber, and has a generally cylindrical form, as disclosed in Japanese Utility Model Early Publication 1-150418. Such grommet requires tedious manipulations in accommodating wiring harnesses since the inner passage must be widened prior to insertion of accepting the wiring harnesses.
In an attempt to improve efficiency in installing grommets, a hard grommet has been proposed in Japanese Utility Model Early Publication 5-36720. A hard grommet is essentially made up of two generally leading members of relatively rigid material like hard plastics. Since it has appropriate rigidity, it is fairly easy to install wiring harnesses through the grommet without widening the passage of the grommet.
However, this type of hard grommet has a disadvantage that the hard members have poor sealing ability between their mating faces and often allows rain drops to come into the grommet through the mating faces. This can happen because the two leading members merely abut on each other on the mating faces.
A hard grommet as disclosed in Japanese Patent Early Publication 3-5008 utilizes soft filler. In this grommet, wiring harnesses are placed between two hinged leading members, which are then mated each other and locked by a lock mechanism provided thereon. The grommet is then dipped in a vinyl chloride plasti-sol so that the entire grommet is covered with soft plastic filler of vinyl chloride, thereby providing necessary water proof film on the grommet. The film is also useful in sealing a gap between the grommet and a grommet hole in which the grommet is installed. However, this type of grommet has a disadvantage in that it has a rather complex configuration and hence requires complex manufacturing steps. Furthermore, once the vinyl chloride film is formed on the grommet, they cannot be disintegrated for reuse.
The Japanese Utility Model Early Publication 5-35720 also discloses a grommet which includes two-part hard inners. The grommet is not provided with any sealant. That is, the hard grommet is adapted to fit loosely in a grommet hole. Thus, the grommet fails to stop the raindrops coming through the hole.
Another disadvantage pertinent to these hard type prior art grommets of the is that they must be forced into a grommet hole in a panel by a relatively large might, requiring extra effort by a worker.
A grommet is also used to hold wiring harnesses in desired configuration in a given position. For example, a grommet disclosed in Japanese Utility Model Early Publication 6-27255 utilizes a bellow for flexibly holding wiring harnesses in a narrow space. With this grommet, however, it is difficult to constrain wiring harnesses in a desired orientation because of the flexibility of the bellow.
It is, therefore, an object of the invention to provide an improved hard grommet having hard sections for receiving there between wiring harnesses without difficulty as well as a resilient section that may hermetically fit in a grommet hole of a panel in, providing good seal for the grommet hole.
In accordance with the invention, there is provided a grommet which includes a pair of grommet halves. The grommet halves have at least one lock mechanism for locking said grommet halves in coupled condition after the grommet halves are mated together on their mating faces. The grommet halves each have: a generally semi-cylindrical hard member having a mating face; a hard semi-disc member having a mating face; and a generally semi-frusto-conic resilient member joining the leading member and said semi-disc member and having a semi-annular groove and mating faces which are contiguous with the mating faces of the leading member and the semi-disc member so as to form the mating faces of the grommet halves. The leading members, the semi-disc members, and the resilient members form a generally cylindrical hard section, a hard disc section, and a generally frusto-conic resilient section of the grommet, respectively, when mated together. The disc section is larger in outer diameter than the leading section and the resilient frusto-conic section. The resilient section has a circumferential groove formed on its outer surface as a result of mating the resilient members. The annular groove is adapted to receive the edge of a panel defining a grommet hole. When the resultant grommet is inserted in a grommet hole of a panel, an annular groove of the resilient section tightly engages the edge of the panel defining the hole, thereby preventing rain drops from infiltrating through the hole.
It should be noted that the hard cylindrical section and the hard disc section stay on the opposite sides of the panel and retain the wiring harnesses in the desired configurations on both sides of the panel. This is the case even when the wiring harnesses had kinks before they are placed in the grommet.
Most parts of the grommet may be made of materials having less specific gravity than rubber, so that the entire weight of the grommet is notably reduced than that of a conventional rubber grommet.
It should be also noted that the resilient section has enough elasticity to allow for deformation experienced during its installation into the grommet hole. That is, the grommet may be easily inserted in the grommet hole with a little might. The grommet halves may be unlocked and disintegrated, if desired, so that they can be reused repeatedly.
The grommet of the invention may be provided with resilient seals between the mating faces of the grommet halves, which provides water-proof seal between them, so that rain drops are prevented from entering into the grommet.
In another aspect of the invention, there is provided a grommet having a bent configuration for holding wiring harnesses in a specified configuration. This grommet is advantageous in holding wiring harnesses in a desired configuration in a limited space.
The grommet may be provided with means for holding another element at a specified position. For example, the grommet may hold thereon a connector for conveniently connecting some of the wiring harnesses diverging from the grommet with other electrical devices.